Automatic train-control system



M. L. SINDEBAND -AUTOMATIC TRAIN CONTROL SYSTEM Jan. 11 1927.

Original Filed July 21, 1921 IN VENTOR VWM QLJ ,a/wkaJ W i Zfi MAJ, m5 mi any block or section is abnormal (due for example to the presence of a train in that block) the polarity of the opposite rails of the adjacent section in the rear will be reversed- The relays R, R, R", are neutral relays: i. e., each of them is capable of maintaining its armatures in the attracted position when energized by current of normal or reverse polarity.

The system as thus far described may not 0111 be employed to control the train-carrie system hereinafter described, but also to control way-side signals. Thus each of the sections B,B' and B" is shown as provided at, or adjacent, its entering end, or a suitable distance in the rear thereof, with a some hore or other signal S, S, S". The signal is provided with suitable actuating mechanism. (not shown)- which, when electrically energized, maintains it in clear positionr When tie-energized, the signal assumes its [biased position, i.e., it indicates danger. The signalcircuit' includes front contacts 15,15 of relay R and a battery or other suitable-source of current G. When the section or block '13 is clear and otherwise normal, the signals will be held at clear by current flowing from the battery G through the signal S and'contacts 15, 15

back to battery. If the section B is occupied by a train or is otherwise abnormal, the relay R will be de-energized-and the last-traced circuit broken at contact 15, thus setting'the signal S at danger. The connection for the signal S, including contacts 115, 115 and battery G, and the connections for the signal S", including the contacts 215, 215 and battery G, will be understood in view of the foregoing description in connection with the signal S.

The'wheels upon one side of a train are commonly connected, electrically, to the corresponding wheels upon the other side through the axles. 3 I have found by actual test, that when a locomotive enters a track section such as sections B, B, etc.', the

leading or first axle carries about per cent or more of the short-circuit current. In other words. there is quite a difference between the values of the current flowing through the first axle to enter ,a section B,

B or B" and that flowing through the last axle of the same locomotive in the same Section. This fact should be borne in mind as upon it degends the operation of the system'hereinisclosed.

If the road be a steam road I' prefer to employ the first truck axle in'the direction of traflicand the last axle on the tender as. a part of the means for coupling the scribe a preferred form of trainor vehiclecarried instrumentalities forming a part of the invention. 1 b

Two identical, or substantially identical, closed cores 22, 23 are suitably mounted upon the vehicle, each surrounding a corresponding one of the axles 20 and 21, respectively. Each of these cores is of iron, selenium steel, or other suitable magnetizable material, and each is preferably laminated. Each of the cores 22,23 is shown provided with aprimary winding 24 or 25, said primary windings being of the same number of t rns, wound in the same sense, and serially connected with each other in the samesense across a suitable source of alternating E. M. R, such as an alternating current generator 26. Each of the corescontrol a vehicle-carried signal, orvehicle speed-controlling instrumentalities, or both. This may be accomplished by means of the following mechanism.

The relay 33, in one of its positions .bridges, orelectrically connects, a pair of "contacts 35, 35, another pair of contacts 36, 36being open at this time. In another of its positions, the relay 33 bridges the contacts 36, 36, the other contacts 35, 35 being open at this time. The contacts 35, 35' are shown connected in series with a battery 37 Y and the coil 38 of an electro-.

magnetically operated valve 39 in the air line or train pipe 40 forming a part of the usual air-brake system mountecl' upon the vehicle. VVhe'n the contacts 35, 35 are closed the coil 38 is energized and the brakes are not applied but when the contacts 35,

35 are open the relay 38 is tie-energized. the line 40 is opened and the bralres applied.

The parts 22, 23, 24,25, 29, 30*, 31, 32 and 33 are so designed that when there is no current flowing in axles20 and 21 the M. F.s i

induced in the coils or windings 2?; and 30 are exactly equal and opposite so that no current will flow throu h the coil 31 of the two-phase relay 33. The effect of any current through, axles 20, 21 of a frequency lower than that of the; alternator 26, is to change flux conditions in the core. At this point it may be stated-that any current flowmg through axles-20 and 21 is to be regarded as alternating current-direct current being considered as alternating current of .zero frequency. If the currents in the axles 20 and 21 were equal and in the same sense, the flux-changgs inthe cores 22 and, 23 would be identica so that the voltages induced in windings 29 and would 'still be equal and no current would flow in phase 31 of the relay 33. However, if the current in the axle 20 exceeds that flowing in the same direction in the axle 21 the .E. M. F. induced in one of the windings 29, 30 will prepon-- derate over that induced inthe other of said windings and a current will flow through the relay coil 31. The direction of flow of the last mentioned current will depend upon the direction 'of flow 'ofcurrent through the axles 20 and 21. When the coil 31 is de-energized or when energized by current flowing in one direction, the relay 33 causes the bridge between the contacts 35, 35 to be broken. When the coil 31 is energized by' The block B" is clear and normal, The relay R is therefore energized and current flows from the battery C, through contacts 111, one side of track section B", axles 20, 21, the other sideof the track section .B, contacts 114, backto-batterv G. The direction of flow of current is indicated by arrows in Fig. 1. Under these conditions the balance between the coils 29 and 30 is destroyed and'current flows in such directionin the coil 31 pf the relay 33 as to cause the latter to bridge the contacts 35, 35, to maintain the coil 38 ener ized so that the brakes are not applied. I the battery .0" should fail, or should become short-circuited ahead of the vehicles, or the circuit includingthe battery and rails of section B should become broken, there would be no current flowing in the axles 20 and 21. In this event the coil 31 of relay 33 -would become de-energized and the contacts35, 35 would be opened to vent the train pipe 30 and apply the brakes. The system is therefore biased so as to stop the train ifabnormal conditions exist. it

will be noted also that the signal S is clear is re-energized, icks up its core and signal S" assumes the clear position. The block B being clear, the coil 31 is energized 'in such a direction that the contacts 35, 35 will remain bridged and the vehicle brakes will not be applied, as will be readily understood in view of the foregoing description. As same now that, with the first train .in block B a second train enters or attempts to enter block B". The first train will have shunted out the coil of the relay. R causing the latter to disengage its front contacts and to cause the back'contacts to be bridged. Gurrent will then flow through the axles 20, 21 of the second train (in section B") in a di rection op osite to that in which it would have flowe if the block B were clear. The coil 31 of relay 33 will thus be energized by current flowing in such direction as to cause the relay toopen contacts 35, 35 to cause brakes to be ap lied to the vehicles' Obviously, if the re ay R had been shunted out by something other than a train, orif the battery C should fail, or if either connection between the battery C and relay R should -fail,the relay B would be de-energized to stop a train in the block B". If the battery 37 should fail or its circuit become broken in an way, the train carrying that battery woul be stopped. If the coil 31 is deenergized due to any cause such as a break in the circuit of the coils 29, 30 and 31, the vehicle would be stopped. If the circuit between the coils 24, 25 and the generator,

should break, the train would bestopped. In short it will be appreciated that I have,

provided a system which, in spite of its great simplicity, is thoroughly reliable and which, u 11 failure of any of its component parts, Wlll stop the train or trains until the cause for failure has been remedied. If any block be occupied by a vehicle,'a vehicle in the preceding bloclr will be brought to a stop automatically In addition to the above mentioned advantages, I wish to point out that, except for such line wires as are required for the way-side signals S, S, S", etc., no line wires need be employed in my system. I i

' Numerous modifications may be made in the system above described. For example, 1

it may be desirablenot. to remove the control of the vehicle from the engineer, or

motorman, even when the vehicle is in a danger zone but rather to permit him ta proceed at a speed such as will permit him to stopthe vehicle quickly. This may be accomplished by employing instrumentalities shown at the left of Fig. 2, or the equivalent thereof. In Fig. 2 l have shown speed controlled contacts 50, 51 shunted across the contacts 35, 35. lif'the contacts 50, 51' are closed the vehicle brakes will not be applied because of the current flowingthrough the-following path: from battery 37, through contacts 50, 51, electromagnet 38 and back to battery. ,Means are provided for maintaining the contacts 50, 51 closed so long as the speed of the vehicle is below a predetermined amount, say 15 miles per hour, and for opening the con tacts 50, 51, when that speed is exceeded. This means may assume various forms among which is that illustrated.

'The pivoted contact 50 is biased away gage atone end the slidin follows.

from fixed contact 51 by any suitable means, long as the danger exists. When the light such as a spring 52, and isadapted to en- 60is extinguished the engineer will proceed. It is believed that the operation of. that sleeve 53 of a centrifugal governor 54 dr ven by any one part of the system which embodies the eleof the vehicle axles 55 through gearing56, ments to and 29, 30, will be under- 57. These. arts are designed to'operate as stood by those skilled in the art, in view When the speed of the vehicle is of the foregoing disclosure. I may state, at or below a predetermined value, say 15 however, that I now believe the theory of miles per hour, the contacts 50, 51 are mainsuch operation to be similar to that set forth tained closed by the governor 54, through in the copending application filed by me on its sleeve 53. If that speed is exceeded, September 20, 1920, Serial No, 111,479,. even slightly, the. governor 54- elevates its The sensitivity of the coupling between sleeve 53 to permit the spring 52 to disengage the track and vehicle-carried portions of the per hour. Under such conditions the c0nbe so selected, with respect to the magnetizatacts 50, 51 would be closed and the eleetro tion curves,.as to cause a maximum response should attempt to exceed the s the contact 50 from the contact 51. If the system -may be increased or controlled by means last described be incorporated in the superimposing fluxes upon the cores 22, 23 system the operation will be readily underby themear s shown at the lower right-hand stood in view of the foregoing description part of Fig. 2, or means equivalent therecoupled with the following explanation. to. Coils or windings 71, 72- are provided Assume that there is a vehicle in the upon the cores 22, 23, each of these coils block B and a following vehicle attempts-being of the same number of turns as the to enter block B. The contacts 35, 35'Wlll other. These coils are shown as wound in then open on the following vehicle and if the the same direction but serially connected in contacts 50, 51, were not provided the fol5 opposition to each other in a circuit includlowing vehicle would lee-stopped automat1- ing a variable resistance.- 73 and a battery cally. However, by virtue of the contacts or other suitable source of E.' M. F. 7%.

50, 51 and the governor device the following By properly adjusting the resistance 73, the train may proceed at a speed-under 15 mlles average flux density in the cores 22, 23 may magnet 38 energized. If, while block B inthe circuit 29, 30, 31, upon the heretois still occupied by the leading train, the fore mentioned variations 1n the curren driver of the following train in blgckfig; flowing through the axles 20, 21. imposed (i. e'., 15 miles per hour the coninductive one in the sense that this term tacts 50, 51 would open to de-energize coil -is commonly employed'in-the art The effect 38 to cause the brakes to be'applied. 'If the of currents in the axles or conductors 20, 21 signal S be placed in the block B, adjais not to induce currents in the transformer cent the entrance of the block B, its mdicacoils from the trackcircuits but rather to tion would advise the driverof the follow vary flux conditions the cores 22, 23 to ing vehicle as to whether or not he may shiftthe points on the magnetization curves enter section B. with safety. If the si al at which the cores operate. The ultimate S indicates danger the following driver effect is to create an unbalance in the E. M. should stop his vehicle, while if it stands at F.s of coils 29, 30, induced by coils 24, 25. clear he may proceed with safety at full The diflerence between my's stem and an in speed. ductive one will be appreclated when it is A cab signal may be employed instead of, borne in mind that unidirectional currents or in addition to, the speed-controlling mechof constant amplitudes (but dilferent amplianism above described. The control of tudes) in the axles 20, 21 will produce a such a signal may be eflected through the response in thecircuit of coils 29, 30. contacts 36, 36 of the relay 33. This signal As previously stated, either or both of the may assume the form of a red, .or other devices 38 and 60. may be employed. The suitably-colored, lamp connected in series signal60, if'employed, guides the driver in with the contacts 36, 36 across the battery the operation of his car. The brake-con- 37. Bearing in mind that the contacts 36, trolling ma et' 60, if employed, automati- 36 are bridged whenever conditionsahead callycon tro sthe speed of the vehicle. Either It wlllbe noted that my system is not an are abnormal (due to a train in the-block of these devices 38 and 60 may therefore ahead, or failure of one or more of the be termed traflic-controllingJneans, and sources of E. M. F., or breakage of one or it is in this sense .that- I have employed the more of the electrical conductors,'etc.), it last mentioned expression in certain of the will be appreciated that the lamp 60 will be ap ended claims.

energized so long as the abnormal condi- V tion exists. If a train carrying the signal patent statutes, I have herein described the 60 be stopped, either automatically or by principle of operation of my invention, tomanual 0 ration by the driver, because of gather with the apparatus which I now condanger ahzad, the lamp 60 will be lit so sider to represent the best embodiments n accordancewiththe provisions ofthe thereof, but ll desire to have it understood that the apparatus disclosed is only illustrative and that the invention can be carried out by other .means. Also While it is designed to use the various features and elements in the combinations and relations described, some of these may be altered and others omitted without interfering with the more general results and efibcts outlined, and the'invention extends to such use.

What 1 claim is i. In combination, a railway track divided into a plurality of sections, means'for im pressin an F. across the opposite rails oi each section, means for controlling the E. M. F. of each section by a section in advance in the direction of trafiic, a railway vehicle having spaced conductors which electrically connect the opposite rails of a section occupied by said vehicle, and vehiclecarried means controlled by the relative character of the currents through said con ductors for governing the speed of said vehicle.

2. In combination, a railway track divided into a plurality of sections, means for impressing an E. F. across the opposite rails of each section, means for controllin the relative polarity of the opposite rails of each sect1on 'by the section in advance in the direction of traffic, a railway vehicle having s aced conductors which electrically connect t e opposite rails of a section occuied by said vehicle, an impedance carried By said vehicle and inductively coupled to one-of said conductors, a second impedance carried by said train and inductively coupled to another of said conductors, and means governedby said-im dances for controlling the eed of said ve :cle.

3. n combination, a railway vehicle having a plurality of spaced conductors each adapte to electrically connect the opposite rails of the track over which said vehicle travels, a transformer carried by said vehicle and inductively associated with one of said conductors, a second transformer carried by said vehicle and inductively associated with another of said conductors, trafiic-controlling means carried b said vehicle, and means controlled by electrically opposed windin of said transformers for governing said trafiic-controlling means. v 4. In combination, a railway vehicle, a magnetizable core mounted adjacent an axle of said vehicle, a second magnetizable core mounted adjacent anotheraxle of said vehicle, a winding on one of said cores and a winding on the other of said cores, trafiiccontrolling means carried by said vehicle, and means carried by said vehicle and electrically connecting said windings in. opposition for controlling the said traflic-controlling means. i

5. In combination, a railway vehicle, a

Eli

pressing E. M. F.s across the opposite rails of each section of a frequency different from that of said magneto-motive forces, means for governing the E. M. F. of each track section b a section in advance, a winding on one 0 said cores, a winding on the other of said cores, and means controlled by the E. M. F.s induced in said windingsfor controlling the speed of said vehicle. 1

7. In combination, a railway track di-' vided into a plurality of sections, means for impressing an E. M. F. across the opposite rails of each section, meansfor controlling the E. M. F. of each section by a section in advance in the direction oftrafiic, a railway vehicle having spaced conductors which electrically connect the opposite rails of a'section occupied by said vehicle, trailic-controlling means carried' by said vehicle, and means controlled by the relative character of thecurrents through said conductors for controlling said trafiic-controlling means.

8. In combination, a railway track divided into a plurality of sections, means controlled by a section in advance for causing a direct current to flow through the rails of each section, a railway vehicle having spaced conductors which electrically connect the opposite rails of'a section occupied by said vehicle, traflic-controlling means carried by said vehicle, and means comprising vehiclecarried impedances each electromagnetically associated with corresponding ones of said conductors and controlled by direct current flowing throu h said conductors for controlling said tra c-controlling means. I

9. In combination, a railway vehicle having a plurality of. spaced conductors each adapted to electrically connect the opposite rails of the track over which said vehicle travels, means for causing current-to flow through said conductors,- .a vehicle-carried winding electromagnetically associated with one of said conductors, a second vehiclecarried winding electromagnetically associated with another of said conductors, means other than said conductors for mpressing an E. M. F. upon said windings,

traffic-controlling means carried by said vehicle, and means electrically connected to said windings for controlling said trafliccontrolling means.

10. In combination, a railway vehicle having a plurality of spaced conductors each adapted to electrically connect the opposite rails of the track over which said vehicle travels, means for causing current of a predetermined frequency to flow through said conductors, a vehicle-carried winding electromagnetically associated with oneof said conductors, a second vehicle-carried winding electromagnetically associated with another of said conductors, means comprising a v0- hicle-carried source of E. M. F. for impressing an E. M. F. upon said windings, trailic carried y the vehicle for impressing alter-- nating magneto-motive forces upon said cores, a track divided into sections, means for impressing E. M. F. across the opposite rails of each section, means for governing the E. M. F. of each track section by a section in advance, a winding on one of said cores, a winding on the other of said cores, traflic-controlling means carried by said vehicle, and means electrically connected to said windings for controlling said trafficcontrolling means.

12. In combination, a railway vehicle having a (p adapte to electrically connect the opposite rails of the track over which said vehicle travels, a magnetizable core electromagneti' cally associated with one of said conductors, a second magnetizable core electromagnetically associated with another of said conductors, a primary winding upon each of said cores, means for impressing alternating E. M. F. upon said primary'windings, a track divided into sections, means for impressing E. M. F. across the opposite rails of each section, means for governing the E. M. F. of each track section by a section in advance, a secondary winding upon each of said cores, a third winding upon each of said cores, means for energizing said third windings, traffic-controlling means .carried by said vehicle, and means electrically connected to said secondary windings for controlling 'said traflic-controlling means.

13. In combination, a railway vehicle having a plurality of spaced conductors each adapted to electrically connect the opposite rails of the track over which said vehicle lurality of spaced conductors eachtravels, a magnetizable core electromagnetically associated with one of said conductors, a second magnetizable core electromagnetically associated with another of said conductors, a primary winding upon each of said cores, means for impressing alternating E. M. F. upon said primary windings, a 'track divided into sections, means for impressing E. M. F. across the opposite rails of each section, means for governing the E. M. F. of each track section by a section in advance, a secondary winding upon each of said cores, traffic-controlling means carried by said vehicle, and means electrically connected to said secondary windings for controlling said traflic-controlling means.

14. Incombination, a track divided into sections, means controlled by a section in advance for impressing an E. M. F. across the opposite rails of each section, a vehicle having a conductor adapted to electrically connect the opposite rails of a section occuied by the vehicle, an impedance carried y the vehicle and electromagnetically associated with said conductor, a second impedance carried by said vehicle and comparatively remote from said conductor, means carried by the vehicle for impressing upon said impe ances an E. M. F. diflerent infrequency from that of said first named E. M; F. trafiic-controlling means carried by the vehicle, and means connected to said impedances for controlling said trafiic-controlling means.

15. In combination, a track divided into sections, means controlled by a section in advance for impressing an E. M. F. across the opposite rails of each section, a vehicle having a conductor adapted to electrically connect the opposite rails-of a section occupied by the vehicle, a core of magnetizable material carried by the vehicle and electromagnetically associated with said conductor, a primary windin upon said core, a vehicle-carried source 0 E. M. F. different 1n frequency from that of said first named E. M. F. and connected to said primary winding, a secondary winding upon said core, a transformer carried by said vehicle comparatively remote from said conductor and having a primary winding and a secondary w1nd1ng,said last named rimary winding being connected to said vehlcle-carrled. source of E. M. F., trafiic-controlling means carried by the vehicle, and means connected to said secondary windings for controlling said traffic-controlling means.

16. The combination set forth in claim 1 in which axles and Wheels of the railway vehicle constitute the spaced conductors.

17. The combination set forth in claim 2' in which axles and wheels of the railway vehicle constitute the spaced conductors.

18. The method of communicating influences to moving trains in conformity with a current of corresponding polarity.

. 19. The method of communicating control influences to moving railwa trains traveling on'tracks divided into bloc s'each having a track circuit, which consists in applying a uni-directional voltage across the track rails at the exit end of each block of a polarity correspondin to the energized or deenergized condition of the' track relay of the block next in advance, producing in a circuitwholly on the car at allpoints in its travel through a block a voltage which is derived from and corresponds in polarity with the current flow in the track rails of that block, and utilizing said voltage on the car for governing cab slgnal or tram control mechanism.

20. In a train control system, the combination with a block signal system having 'po larized direct current track circuit control, of'safety apparatus on a car including a circuit wholly on the car and com rising means for producing a voltagein said circuit derived from and corresponding to' the olar-v ity and absence of current in said trac circuits.

In testimony whereof I hereto affix my signature.

MAURIGEL. SINDEBAND. 

